I inherited my '05 300C from my father. The dealership he purchased it from apparently told him to use 87 octane gas which he did for three years. The car was problem-free until I took it over around 40,000 miles and started using the Chrysler recommended 89 octane.

About 10,000 miles after I started using 89 octane gas the car started to randomly stall. The dealer would clean the throttle body and it would be good for another 10,000 miles before it stalled again. I took it in today to a different dealer and their answer to the stalling problem is: switch to 87 octane and use a fuel cleaner every now and then. They said it would not hurt the engine (I took it to Central Chrysler in Norwood, MA).

The techs felt the car was getting a carbon buildup from the 89 octane gas. I now have two dealerships telling me that 87 octane is recommended. What do you think?

thats interesting what the dealer told you. I have early 05 build (june 04) the was stalling alot and dealer kept saying they could not find anything wrong with it, then i decided to use 87 gas since last july and it has not stalled once. maybe there is some truth to it.

Keep in mind 87 octane has more heat energy in it. It is actually cleaner since octane is an additive that is like oil. Try buying a can of octane booster and lighting it on fire. It won't burn unless you use a torch.

I inherited my '05 300C from my father. The dealership he purchased it from apparently told him to use 87 octane gas which he did for three years. The car was problem-free until I took it over around 40,000 miles and started using the Chrysler recommended 89 octane.

About 10,000 miles after I started using 89 octane gas the car started to randomly stall. The dealer would clean the throttle body and it would be good for another 10,000 miles before it stalled again. I took it in today to a different dealer and their answer to the stalling problem is: switch to 87 octane and use a fuel cleaner every now and then. They said it would not hurt the engine (I took it to Central Chrysler in Norwood, MA).

The techs felt the car was getting a carbon buildup from the 89 octane gas. I now have two dealerships telling me that 87 octane is recommended. What do you think?

Take it to another dealer. Yours doesn't have a fawkin clue what they are saying. And don't mention the 87 octance thing seeing you are leading them in the wrong direction.

I never brought up the change in octane to the dealer. In fact, that's the last thing I would have done. They must have tested the fuel I had in the car because they knew there was 89 in there. Once they mentioned switching back to 87, that's when I figured the switch to 89 must have caused it.

I never brought up the change in octane to the dealer. In fact, that's the last thing I would have done. They must have tested the fuel I had in the car because they knew there was 89 in there. Once they mentioned switching back to 87, that's when I figured the switch to 89 must have caused it.

If you didn't mention it to them, how did they know to tell you to switch back to 87? There is no way to test the fuel in a car.

Please stop directly associating the stalling with the octane, that is really foolish.

The 89 doesn't cause stalling, bad gas does. You got a bad batch of gas and that is what is causing the stalling. It is not the octane so please stop associating the engine stalling from you using the proper octane for the engine.

Go get some water remover and put it into your tank to remove the water and fill up at a GOOD station, not a mom and pop gas n go at the corner.

In tough times, most people won't even use 89 and it will sit in the tanks for longer periods which will have it go bad or collect more water.

That is your problem, not the octane. 1000s here use 89 and we have NO problems.

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